1. Field of the Invention
This invention relates generally to the control of electrical loads such as lamps, and more particularly to the remote and the ambient light control of lighted Christmas tree ornaments, and the like.
2. Description of the Prior Art
Light displays have long been very popular to help celebrate special occasions and major holidays, particularly the Christmas Holidays in the Christian world. Lights for this purpose conventionally are provided as a plurality of brightly colored lamps arranged in sockets strung on electrical wires. Anyone familiar with decorating a Christmas tree or creating an outdoor Christmas display is familiar with the hassle created by the necessity of arranging the wires so as to permit a suitable placement of the lamps without distracting from the appearance of the tree, house, or other structure, in the light of day. In addition, the insulation of the electrical wires often becomes frayed and broken with use, a situation that not only can limit the usefulness of a string of lights, but can create fire and shock hazards as well.
In view of the disadvantages of the conventional strung Christmas tree lights, and the like, it has been proposed to construct Christmas tree ornaments, and the like, having a self-contained power supply. While such an arrangement eliminates the need for the bothersome wires to be connected between the individual lamps, these lights never became popular because of the impracticality of manually controlling the operation of each individual lamp. When one considers the large number of lights normally used on Christmas trees and other light displays, it can be readily appreciated that it is not practical to be manually turning on and off say fifty or more lamps individually.
Accordingly, U.S. Pat. No. 4,866,580, issued Sep. 12, 1989, to C. Blackerby is directed to an ornamental lighting device that can be turned on and off by remote control. The remote control link is formed in this system by infrared light being transmitted to each of the lamps. A difficulty has been encountered with the use of light as a coupling between the remote control systems transmitter and individual receivers, however, inasmuch as some of the lamps may be behind a Christmas tree, for example, and not be in the line of sight of the transmitter, thus requiring a person operating the transmitter to move about in order to turn on or off all of the lamps in a display.
This brings about another difficulty with the conventional remote control systems for controlling lights on a Christmas tree, since repeated actuation of the transmitter will turn off lights already on, or turn on lights already off. U.S. Pat. No. 3,534,351, issued Oct. 13, 1970 to J. D. Harnden, Jr. et al discloses a light coupled remote control apparatus in which a bistable multivibrator is triggered each time it senses one of a series of uniform pulses. Such systems have made the use of self-powered, remotely-controlled lights for Christmas trees and other displays impractical until now.